What do you know.
We will also be in Barcelona a few days earlier (arriving on May 26th) and 3 days after the cruise in Venice. Also made arrangements to see Florence, Pisa and Rome on our own taking the train). We have a special invite from the Vatican to go on the Scavi tour under the Vatican. Should be interesting.
I will prebook train tickets 30 days prior to needing them, this way we don't have to stay in line at the train station.
Would you like to meet in Barcelona so we can compare notes? We can e-mail each other prior to leaving if you like.